Structural, optical and electrical characterization of SnS nanomaterials grown at different temperatures

SnS nanocrystals were synthesized by simple wet chemical precipitation method. XRD results shows that the crystals are orthorhombic in phase. TEM images indicate that the grain sizes are almost spherical within the range 5 nm to 10 nm. Crystalline natures of the samples were confirmed by HRTEM. AFM analysis shows that surface roughness were found to be moderate. EDAX analysis revealed that the samples are maintained good stoichiometric ratio of Sn/S. From UV–Vis absorption spectra it is evident that SnS nanocrystals are good absorbing materials for solar light. PL spectra indicate a red shift of SnS nanocrystals occurred with increase growth temperature. Time correlated single photon counting (TCSPC) measurements revealed that PL decay life times are in the order of picosecond. The temperature varying SnS nanocrystals were p-type in nature with electrical conductivities were ranging from 0.020 to 0.037 Ohm⁻¹ cm⁻¹ and carrier concentrations were 7.05 × 10¹³ cm⁻³ to 1.54 × 10¹⁴ cm⁻³. Carriers drift mobilities were found to be high compared to the reported results. Therefore, SnS nanocrystals having low resistivity, higher drift mobility, higher carrier concentrations, small PL decay life time and high absorption coefficient exhibited excellent properties for the fabrication of optoelectronic devices.